There is known a first embodiment of a punch in which a ram extends along a pull axis which is practically coincident with a longitudinal axis of a pump reservoir, the punch as a whole being straight. In a second known embodiment, the ram is arranged with its pull axis perpendicular to the longitudinal axis of the pump reservoir. The operator chooses the more appropriate punch according to the accessibility of the hole that he has to make.
Thus, according to this known prior art, it is necessary to have two punches, each having a given orientation of the ram with respect to the longitudinal axis of the pump, which leads to high expenditures on the appropriate tools. Furthermore, when using the straight tool to make holes near an end of a cabinet or near another wall, the operator cannot get his hand between the pump and the end or the contiguous wall, and this hampers him in his use of the tool.
In another known embodiment, the pump body is connected to the ram by an elbowed connector, one end of which is articulated with respect to the pump body about an axis which is coincident with the longitudinal axis of the pump, and the other end of which is articulated with respect to the ram about an axis which is perpendicular to the previous axis. The ram can thus be orientated about two perpendicular axes.
This tool has a relatively complicated structure, particularly since the connector is outside of the ram and consists of a relatively high number of parts. Furthermore, at each of the hydraulic connections between the ends of the connector, and on the one hand, the pump body and, on the other hand, the ram, it is necessary to ensure the continuity of the hydraulic circuit. This arrangement therefore demands numerous fastening and sealing elements which increase the complexity of the assembly. Finally, the connector has an elbowed shape, to one of the ends of which the ram is rotatably articulated, and this makes the tool vulnerable to impact, for example if dropped, which is likely to corrupt the articulation of the ram to the connector.